Pump



Sept. 27, 1938. A. G. HORVATH PUMP 2 Sheets-Sheet 1 Original Filed Nov. 17) 1936 INVENTOR. ANTHONY GHORVATH,

ATTORNEYS.

Sept. 27, 1938. G HQRVATH 2,131,623

PUMP

Original Filed Nov. 17, 1936 2 Sheets-Sheet 2 Fig, 6.

3 INVENTOR. ANTHONYG. HORVATH,

A TTORNEYS.

Patented Sept. 27, 1938 PUIVEP Anthony G. Horvath, Dayton; Ohio, assignor to The Dayton Pump & Mfg. (30., Dayton, Ohio, "a corporation of Ohio Original application November 17, 1536, Serial No. 111,265. Divided and this application July. 9, 1937, Serial No. 152,795

9 Claims. (o 103-37) This invention relates, to variable delivery pumps.

It is an object of this invention to provide a constant speed variable delivery pump.

It is a further object of this invention to provide a pump, wherein the capacity is varied directly by the pressure in the tank and indirectl by the quantity of fluid in the tank. I 7

It is a further object of this invention to provide such a pump wherein starting and stopping, during operation, is reduced to a minimum and wherein there is a constant pressure on the deliv- "cry end of the pump irrespective of the variation in the quantity of fluid supplied by the pump.

It is a further object of this invention to provide, between the air chamber and one of the pressure chambers, by-pass means, and between the air chamber and the other pressure chamber of a double-acting pump, diaphragm means, responsive to pressure both in the air chamber and the pressure chamber of the pump.

It is a further object of this invention to pro vide diaphragm means between the air chamber and each of the pressure chambers ofa doubleacting pump.

It is a further object of this invention to provide such means which will vary the fluid delivery inversely with the delivery pressure. 7

It is a further object of this invention to provide pressure responsive means between the air chamber and both pressure chambers in order to vary the capacity of the air chamber of the double-acting pump having two pressure chambers.

It is a further object of this invention to provide such means which will periodically Vary the capacity of the pump, which means is responsive to the pressure differential between the air chamber pressure and the respective pressure chamber pressures in order to vary the fluid delivery of the pump inversely with the delivery pressure.

It is a further object of this invention to provide means for varying the capacity of the air chamber directly with the pressure at the pump delivery, whereby the quantity of fluid delivered by the pump will be varied inversely with the pressure at the pump delivery.

It is a further object or this invention to provide means disposed internally of the pump for accomplishing the above objects.

It is a further object of this invention to provide, in the connecting wall between the air chamber and a pressure chamber in a pump, diaphragm means responsive to the pressure on each side thereof for varying the capacity in the pressure chamber in accordance with change in pressure in the air chamber.

It is aiurther object of this invention to provide, in a double-acting pump, such means disposed between each pressure chamber of the pump and the common air chamber thereof.

It is a-furtherobject of this invention to provide a pump adapted for constant operation, during delivery, with a minimum of starting and stopping and with a wide range of supply without starting and stopping and a high gallonage of delivery per hour per horsepower. 7

It is a further object of this invention to pro,- vide an air cushion, a combined air and water cushion and means for relieving the-fluid pressure delivery and the starting and stopping operations with a consequent saving on the pump and motor.. These and other objects and advantages will appear from the following description taken in connection with thedrawings.

This application is a division of my application Serial No. 111,265, filed'November "17, 1936.

In the drawings:

Figure 1 is a side elevational View, partly broken away, of an illustrative form of pump for which the principles of my invention are particularly adapted;

Figure 215 an end elevational view of the pump V shown in Figure-1;

, Figure 3is a plan view, in section; taken along the line 33 of Figure 1;

Figure lis a sectional view ofthe air chamber of the pump taken on the line 4+4 of Figure 1,

showing the attached pressure switch partly in 35- I V section; r V

Figure 5 is a fragmentary sectional view of structure "shown inFigure 1, illustrating the application of the principles of this invention to the pump structure shown therein;

Figure 6 is a a view similar to Figure 7,. but showing the parts in a second position;

Figure '7 is a fragmentary sectional view similar to Figures 5 and'6, but showing theapplication of a modified form of structure to the pump;

and

Figure 8 is a View similar to Figure 7, but showing the parts in a second position.

Referring to thedrawings in detail and, in

particular,- to Figures 1 and 2, l designates the sub-base of the pump upon which is'rigidly secured the pump casting 2. The crankcase 3 is formed at oneend of the pump casting 2, and above the crankcase 3 is a motor platform 4 and V crosshead' guide'eylinder 5. At the opposite end of the pump casting 2 and integrally formed therewith is the suction inlet chamber 6 having a pair of intermediate chambers 7 and la disposed at opposite sides thereof. Provision is made for the attachment of suction inlet 8 at one side of the suction chamber 6. The suction inlet is also attached to a primer vacuum chamber 9 which is equipped with suitable interior suction strainer screen (not shown), and at the top with a priming plug l0, and at the bottom with a cleanout plug Suitable bearings are provided in the crankcase portion of the casting 2 for support of crankshaft |2 which is operatively connected by means of connecting rod |3 to the crosshead M which is mounted for reciprocation in the crosshead guide cylinder 5. Disposed on the motor platform 4 is the motor 5 or other suitable prime mover, which is operatively connected to the pulley l6 rigidly attached at one end to the crankshaft l2. 6 By this means the crosshead I4 is caused to reciprocate in the crosshead guide cylinder 5 during operation of the prime mover.

Attached at one end to the crosshead l4 and disposed axially thereof is thepiston rod I1, which passes through a fluid deflector H3 at the end of the crosshead guide cylinder 5, which deflector prevents the. entry of fluid on the piston rod into the crosshead guide cylinder '5 and thence to the crankcase. Extending across the suction chamber Sis an open-ended cylinder 20 which has its opposite ends in communication with the respective intermediate chambers 'l and 1a. A stufiing box 2| is threadedly attached to the outer wall of the intermediate chamber 1 and the piston rod l'i' which is axially disposed with respect to the stuffing box 2| and cylinder 28 extends through the stuffing box and has the piston assembly 22, which is adapted to reciprocate in the cylinder 29, attached to the threaded end thereof. The casting 2 terminates above the suction chamber'fi and intermediate chambers and la in a flat wall, to which is attached the casting 23 forming the pressure chamber as a whole, which is divided into two parts or pressure chambers 25 and 25a respectively by the dividing wall 24.

A piston plug 28 equipped with a Schrader valve 21 and Ma diameter suitable to provide easy access to the cylinderand piston assembly is threaded into the outer. wall of the interme diate chamber la. The pressure chamber 25 is.

connected Icy-means of suction valve assembly 29 with the-suction chamber 6. The pressure chamber 25a. is connected by means of suction valve assembly 290, with the suction chamber 6. The casting 23 has a top wall upon which is suitably secured a' casting forming an air chamber 35 having a priming plug 3| screW-threadedly attached at the top thereof and having a delivery outlet 32 offset therefrom, which is adapted to be connected to a conventional tank in a fluid system in which the pump is connected.

Screw-threaded in the air chamber 3|] and disposed above the outlet 32 is a choker nipple 33 which supports a conventional pressure switch 34 which is connected by means of cable 35 with the motor 5 and which responds to pressure in the air chamber to start and stop the motor IS in a known manner. The interior of the air chamber 3|! is equipped with a horizontal wall 36 having aconstricted port 3'! therein. The air chamber 38 is connected to the pressure chamber 25 by means of discharge valve assembly 39. The air chamber 38 is connected to the pressure chamber 25a by means of discharge valve assembly 39a.

The valve assemblies 29, 29a, 39 and 39a are identical and comprise apertured plates cooperating with resilient valve plate members resili'ently urged thereagainst by means of springs, the resilient guide plates being guided by vertical posts attached at one end to the apertured plates and having the upper headed end thereof adapted for abutment with the upper end of the spring which has its lower end in contact with the resilient valve plate. Suitable gaskets are provided between the air chamber and the casting 23 and between the casting 23 and the casting 2, as well as between the stuffing box 2| and the latter casting, and between the piston plug 29 and the latter casting so that the escape of fluid at all joints is effectively prevented. v

The suction chamber is connected through the primer vacuum chamber 9 to a source of fluid supply, and fluid is pumped from the suction chamber 5 through the suction valves 29 and 29a. to the pressure chambers 25 and 25a, and discharge valves 39 and 39a to the air chamber 30 and thence through outlet 32 to a suitable tank or, if desired, directly to the fluidsystem. While an electric motor is shown and described asa prime mover, it is, of course, to be understood that the principles of my invention may be practiced by other desired prime movers and that the 38a is provided between the pressure chamber 25a on the air inlet side of the pump and the air chamber of the pump. A diaphragm- 4-9 is provided between the air chamber and the pressure chamber 25 at the opposite side of the pump,

which diaphragm is responsive to the difference in pressure existing between the air chamber and the pressure chamber 25. The diaphragm mechanism, as disclosed in Figures 5, 6, '7 and 8, comprises an externally threaded cylindrical body portion 4| which is threaded into the top wall of the casting 23 to communicate with both the pressure chamber 25 and the air chamber 30.

At each end of the body portion 4| is attached a cap member AZ'which is provided, at its inner side-with a guide adapted to engage and support one end of a coil spring. The cap members 42 are provided with centrally arranged apertures, by means of which communication of the respective cup washers 43, hereinafter described,with the air chamber and the pressure chamber is achieved. The cup Washers 43 are arranged for reciprocatory movement in the central bore of the body portion 4| and are separated by a metallic plate 44 disposed therebetween. The cup washers have their flanges disposed outwardly toward the opposite ends of the body member 4|. Between each of these cup washers 53 and the adjacent cap 42 is interposed a compression spring. The lower of these compression springs is disposed at one end of the body portion opening into the shown in Figure 5, when the chamber 25 is under pressure and also when the difference in pressure between the air chamber 3i) and pressure chamber 25 is equal to, or less than, the difierence in strength between the springs 45a and 45. In other words, whenever the sum of the fluid pressure and the spring pressure on the top cup Washer 43 is less than, or equal to, the sum of the fluid pressure and the spring pressure on the lower cup washer 43, the parts remain in the position shown in Figure 7, whereby the effective volume or capacity of the chamber 39 is unchanged by the diaphragm 49. Likewise, the effective volume or capacity of the chamber 25- is unchanged, under these conditions, by the diaphragm 40.

The upper springs 45a are, in effect, merely shock absorbers and other means, such as a rubber stopper or the like, may be substituted therefor. It will thus be seen that the springs 45a and 45 may be so balanced that the diaphragm will not act to increase the effective volume or capacity of the chamber 3!] until a predetermined pressure is produced in the system (and in the air chamber 30 which is connected thereto). Other adjustments are, of course, comprehended by'me in the practice of the principles of my invention.

As shown in Figure 5', when the pump piston is traveling tothe left and the parts are in the position therein shown, fluid passes through the valve assembly 39 from the pressure chamber 25 to the air chamber 30, while a portion thereof, varying directly with the difference in pressure between the chambers 30 and 25, and varying directlywith the pressure in the system and in the chamber 30, will pass through the by-pass orifice 38a from the chamber 30 to thechamber 25a. During this stroke, the capacities of the chambers are unmodified by the diaphragm).

As shown in Figure 6, in which the difierence in pressure between the air chamber 30 and the pressure chamber 25 is taken as great enough to cause compression of spring-45, and. in which the piston is traveling to the right, as seen in Figure 1, the pressure chamber 25a is under compression, while the pressure chamber25 is under suction. Fluid flows from the pressure chamber 25a through valve assembly 29a and through by-pass orifice 38a to the air chamber 30.

The cup washers of the diaphragm 45 are depressed against the pressure of the spring 45, whereby the volume of the air chamber 30 is increased and the volume of the pressure chamber 25 is decreased. Considered in another way, the diaphragm has then temporarily increased the pressure in the pressure chamber 25 and has decreased the pressure in the air chamber 35.

When desired, I may omit the orifice 38a bemanent effective volume thereof. Likewise, when the chamber 25 is under pressure, the diaphragm 4|] will be inefiective to modify the capacities of the respective chambers.

"Likewise',1 as illustrated in Figures 7 and 8, I may use, in addition to the diaphragm 40 interposed between the air'chambertt andfthe pressure chamber 25, a similaridiaphragm Miasimilan-v ly disposed between the air, chamber 30. and the pressure'chamber 25a. .As shown diagrammatically in Figures 7 and 8, when the parts are inthe position illustrated in Figure 7; and thepump piston is traveling to the left,- as seen in Figure 1,- the diaphragm 40 will be ineffective to decrease the pressure in chamber-25, which is then under pressure,-or to decrease the pressure in the air chambertii, while the diaphragm 48a is simultaneously decreasing the pressure in the chamber Silby increasing the effective volumeor displacement thereof, whileincreasing theipressure, or decreasing the vacuum in the chamber 25a, which is then under suction, but tending to decrease the volume or capacity thereof and thus decrease the amount of fluid drawn therein during,

the suction stroke thereof.

,As shown in Figure 8, on the reverse stroke I of the piston,the same action occurs, save that the functions of the respective diaphragms 40 and Mia are, in that case, reversed. a

As explained above in the description embodiment illustrated in'Figures 5 and 6,'as the mean effective pressure in the air chamber 30 increases upon increase of pressure in the pump system, the mean effective volume, displacement or capacity of the chambers and 25a decreases. Thus-the mean effective capacities or volumes of the chambers 25' and 25a vary inversely. with the mean effective pressure in the air chamber 30.- As the spring 45 of each diaphragm follows of the Hookes law, the compression thereof will vary,

directly as the pressure in the air chamber 30 because the spring overbalancing pressure will vary directly with the pressure in theair chamber 30.

As willbe clearly understoodtheefiectsiof the by-pass orifice 38a and diaphragm 49in the embodiment illustrated in Figures 5 and 6 will be dependent upon the pressuredifferential' between the airchamber 3i and the respective pressure chambers 25'and 25s. The particular character-- istics of the pumpoperation are further dependent 'upon the. sensitivity or strength of the opposed springs and 45a illustrated in the diagram. Likewise, the strength of the opposed springs 45 and ifia may be varied to secure further modification of the operating"characteristics of the pump; l

In any event, both in the embodiment disclosed in Figures 5 and6 and in the modification thereof (which, though not illustrated, has been described as being similar 'to those disclosed in Figures 5 and 6, save for the omission of the orifice 38a), the pressure differential between the air chamber 36 and the chamber 25 will be de- I creased by the diaphragm 4! when the pressurew differential exceeds a predetermined value. Thus,

when thepressure in the air chamber 38 is increased, the amount of fluid passing into this chamber from the chamber 25 is decreased,

Thelcapacity of the pump of this invention is automatically controlled so that the fluid deliv ered by the pump is varied by varying the effectivevolume of the pumping chamber in inverse proportion to the pressure in the air chamber disposedon' the delivery side of the pump. This is brought aboutby varying the volume of intake in the pressure chambers 25 and 25a by returning a portion of the air from the chamber 30 or a quantity of fluid through the by-passorifice 38a. The quantity of fluid returned varies di- 75 rectly with the pressure in the system. This allows a greater amount of fluid to be returned to the piston chamber at-higher pressures than at lower pressures, that is a variable capacity water pump is provided so that the amount of water being delivered by the pump within a given range depends upon the demand for the water, while the motor driving the pump is maintained at a constant speed.

Likewise, in the embodiment illustrated in Figures 7 and 8, the pressure differential between the air chamber 30 and both pressure chambers 25 and 25a will be decreased by diaphragms 40 and 40a by an amount which will vary directly with the pressure in the air chamber. The amount of fluid passing into the air chamber on each reciprocation of the pump piston will likewise be lessened by an amount varying directly with the pressure in the air chamber 30. Thus, in each of the embodiments described, the delivery of the pump will vary inversely with the pressure in the air chamber 30. The pressure in the air chamber 30 being identical with the delivery chamber or tank pressure of the pump, the delivery of the pump will, therefore, vary inversely with the delivery pressure of the pump.

While I have illustrated only one form of diaphragm, it is, of course, to be understood that various other types of diaphragms may be used for the same purpose. Likewise, if it is desired to unbalance the deliveries of fluids from the respective chambers 25 and 25a, this may be accomplished by suitable variation of spring pressure onthe respective diaphragms M1 .and 40a, by variation of the size of the by-pass orifice 38a. and/or the use of more than one diaphragm, where one has been illustrated, and/or the use of diaphragms of different sizes and/or characteristics.

It is furthermore to be understood that the provision of the by-pass orifice 38a, when such is utilized, is totally independent of the provision of the conventional priming slots formed in the valve seats. In the embodiment illustrated in Figures 7 and 8, two or more diaphragms may be substituted for either or both of the diaphragms there shown. The same result maybe accomplished by the substitution, for one of the diaphragms shown, of .a diaphragm having greater cross sectional area. When a pump constructed accordingto the principles of my invention is applied to'a fluid pressure system including an-air pressure tank, withdrawal of fluid from the system causes entry of air into the tank. After the entry of air into the tank, the air intake valve remains closed.

If unequipped according to the principles of my invention, the pump would tend to deliver to full capacity until the pressure in the tank and in the system were raised sufficiently to cause the pressure switch 34 to shut down the motor. However, due to the incorporation in the pump of the principles of my invention, the delivery of the pump will be progressively decreased with the increase of pressure in the system, whereby to prevent undue starting and stopping of the motor and undue wear upon the pump and the motor. This is due to the provision of the by-pass orifice 38a and diaphragm 40 in the embodiment illustrated in Figures 5 and 6, and to the provision of the double diaphragm means 40, 40a in the embodiment illustrated in Figures 7 and 8, and to the provision of a single diaphragm means in the above described unillustrated modification.

By the provision of these means, the pump is given a capacity which varies inversely with respect to the pressure of the system, because of the above described lessening of the intake in the pressure chambers 25 and 2511 and/or the return from the air chamber 30 of a quantity of fluid through the by-pass orifice 3811 (when utilized), which quantity varies directly with the pressure in the system. The incorporation of the above-. described features in the pump permits of greater increase of displacement without loss of prime than is otherwise possible.

As is diagrammatically illustrated in my cpending application Serial No. 111,265, filed November-l'l, 1936, of which this application is a division, a pump equipped according to the principles of my invention, when compared with a similar but unequipped pump, operates in a substantially more eflicient manner than the une-. quipped pump. For instance, it has been found that, where a conventional 250-gallon per hour pump starts and stops seven times per hour, a 300 to ZOO-gallon per hour variable capacity pump, equipped according to the principles of this invention, delivers a steady stream of water at the constant pressure of 45 pounds per square inch and requires twelve minutes to build up the pressure from 25 to 45 pounds per square inch, whereas the unequipped 250-gallon per hour pump starts and stops seven times per hour and runs after each start for a period of seven and onehalf minutes, is then stopped for one minute, and then completes the following on period of seven and one-half minutes. Wear on the pump is thus substantially decreased over that of a pump unequipped with the principles of my invention and, in addition, the'load which may be carried by a pump of a predetermined capacity or gallonage is substantially increased. Furthermore, the undesirable noise of intermittent starting and stopping of the pump, where internal combustion prime mover means is used therewith, is substantially decreased.

It will be understood that the above-described structure is merely illustrative of the manner in which the principles of my invention may be carried out and that I desire 'to' comprehend within my invention such modifications'as come within the scope of the claims and the invention.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a pump having an air chamber and a pumping chamber adapted to supply fluid thereto through a discharge valve, means for varying the delivery inversely with'the pressure in said air chamber comprising reciprocating diaphragm means connecting said air chamber to-said pumping chamber. U I

2. In a constant speed pump having an air chamber and a pumping chamber adapted to supply fluid thereto through a discharge valve,

means responsive to the pressure in said air chamber for varying the delivery of said pump at constant speed by varying the capacity of said pumping chamber.

3. In a constant speed pump having an air chamber and a pumping chamber adapted to supply fluid. thereto through a discharge valve, means for controlling the delivery of said pump by varying the eifective volume of said pumping chamber in inverse proportion to the pressure in said air chamber.

4. In a pump having an air chamber, a pumping chamber adapted to supply fluid thereto, and valve means adapted to provide communication between said pumping chamber and said air chamber in one direction, means for varying the delivery of said pump in inverse ratio to the pressure in said air chamber comprising a reciprocating diaphragm means connecting said pumping chamber and said air chamber.

5. In a pump having an air chamber and a pair of pressure chambers adapted to supply fluid alternately thereto, means for decreasing the flow of fluid supplied by said pressure chambers to said air chamber by decreasing the efiective volume of said pressure chambers, said last-named means comprising diaphragms connecting said air chamber with each of said pressure chambers.

6. In a pump having an air chamber and a pair of pressure chambers adapted to supply fluid alternately thereto, diaphragm means connecting said pressure chambers and said air chamber for decreasing the flow of fluid from said pressure chambers to said air chamber by varying the capacity of said pressure chambers in inverse proportion to the pressure in said air chamber.

7. In a pump, an air chamber, a pumping chamber, valve means providing communication between said air chamber and said pumping chamber, and means for varying the delivery of the pump inversely with the pressure in said air valve means in said wall providing communicaw tion between each of said pressure chambers and said common air chamber, and pressure responsive diaphragm means in said wall communicating with one of said pressure chambers and said common air chamber.

9. In a pump, a pair of separate pressure chambers, an air chamber, a wall separating said air chamber from said pressure chambers, valve means in said wall providing communication between each of said pressure chambers and said common air chamber, and separate diaphragm means in said Wall providing communication between each of said pressure chambers and said common air chamber for varying the capacity of said pressure chambers in response to variation in the pressure of said common air chamber.

ANTHONY G. HORVATH. 

